Lightroom Search functionality behavior changed

Since the latest Lightroom update, the search function no longer appears to search on the file name - this makes choosing selected photos from a large batch extremely slow and tedious.

In the past, a file name of  e.g. ABC_1234, could be searched for by simply typing 1234 in the search bar, and the correct image would be displayed.

This no longer happens, I have to manually scroll through and look for the file with that number.

I am a corporate portrait photographer, and have large photo batches to get through, Lightroom no longer works for me, as long as I cannot search my work based on file name (or a portion thereof).

Please urgently bring the functionality back.